The multi-store memory model Flashcards
Who came up with MSM?
Atkinson and Shriffin’s (1968, 1971)
What is the MSM?
A representation of how memory works in terms of 3 stores, and how information is transferred from one store to another
What are the 3 stores in MSM?
- The sensory register
- STM store
- LTM store
Describe the sensory register (SR)
Stimulus from the environment enters the sensory register - here there is a register for each of the 5 senses
Visual/ sight information goes into the iconic memory store
Sound information goes into the echoic memory store
The other sensory stores are for smell, taste and touch
What store does visual information go to in the SR?
Iconic memory store
What store does sound information go to in the SR?
Echoic memory store
Describe duration of material in the SR
Duration is very short - less than a second
Describe capacity of the SR
Capacity is very high - eg. the eye has over 1 million cells, all storing data
Describe coding of the SR
Coding depends on the sense receiving the information
Describe the transference from SR to STM
Very little of what goes into the SR passes further into the memory system - attention needs to be given to the information for it to continue
Describe STM in the multi-store memory model
Information in the STM is coded mainly acoustically
Lasts about 18 seconds unless it is rehearsed
STM is a temporary and limited capacity store (Millers 7 +/- 2)
Describe the transference from STM to LTM
Maintenance rehearsal occurs when we repeat (rehearse) material to ourselves over and over
We keep it in the STM until we’ve rehearsed it long enough for it to pass into the LTM
Describe LTM in the multi-store memory model
LTM is a permanent memory store for information that has been rehearsed
It codes semantically
Capacity is unlimited
Duration may be a lifetime
What is the process called when we want to recall information from LTM, so we transfer it back into the STM?
Retrieval
Describe the case of HM (Henry Molaison)
HM underwent brain surgery to relieve his epilepsy. However, the procedure used was in its infancy. A part of his brain known as the hippocampus was removed from both sides of his brain. We now know this to be central to memory function.
HM’s LTM was badly affected by the procedure. When his memory was assessed in 1955, he thought the year was 1953, and that he was 27 years old (he was actually 31). He had very little recall of the operation. He could not form new long term memories. For example, he would read the same magazine repeatedly without remembering it. He couldn’t recall what he had eaten earlier the same day.
However, despite all this, his STM remained in tact and he performed well on tests of immediate memory span.
How does the case of HM relate to the MSM model?
It supports the model as it reinforces the key idea that there are two separate and independent memory stores, STM and LTM.
What happened to HM is evidence that it is possible to sustain damage to one of these stores with the other remaining relatively unaffected.
HM’s LTM was badly damaged. He had no memory for events that happened just hours or even minutes earlier. But testing showed that his STM was much less badly affected. His almost-normal digit span showed that he could recall information that was presented to him immediately.
What do clinical psychologists call the difference in STM and LTM performance?
Dissociation
Give a strength of MSM
Strength - Research support showing that LTM and STM are different. Baddeley’s research showed that for coding STM is acoustic and LTM is semantic. This supports the view that these two memory stores are seperate and independent. The case of HM also supports this, as he proved that when one memory store is damaged, the other one can stay intact and “normal”, showing they’re different.
Give 3 limitations of MSM
Limitation - Artificial materials. Researchers often used digits and letters (Baddeley used words) which had no meaning. In everyday life we form memories related to useful things - faces, names, places. This suggests the MSM lacks external validity. The results may reflect what happens in a lab experiment but not what happens in real life
Limitation - Only explains 1 type of rehearsal. Psychologists (1973) argued that there were 2 types of rehearsal - maintenance and elaborate. Elaborate rehearsal is needed for long-term storage. This is when you link the information to your existing knowledge. Therefore information can then be transferred without prolonged rehearsal. Maintenance rehearsal is going over something over and over
Limitation - Evidence for more than 1 memory store. Shallice and Warrington (1970) studied a client, KF, with amnesia. KF’s short-term memory for digits was poor when they were read out loud to him, however, his recall was better when he read the digits himself. The MSM states there is only 1 type of STM store but this study suggests there must be more - one for visual information and one for auditory information
